vue-tsc: JSDoc comments not emitted when using type-only defineProps macro

[Jak-Ch-ll]

Problem

When generating declaration files for Vue components with vue-tsc --declaration --emitDeclarationOnly no JSDoc Comments are emitted when using type-only defineProps.

I found a few issues regarding JSDoc and defineProps, but most of them deal with default values (such as #2398). And non does describe this issue.

Example

Consider the following component:

<script setup lang="ts">
defineProps<{
  /**
   * This is an example prop
   */
  foo?: string;
}>();
</script>

<template>Hello {{ foo }}</template>

The following Example.vue.d.ts file is emitted with the comment missing:

declare const _default: import("vue").DefineComponent<{
    foo: {
        type: import("vue").PropType<string>;
    };
}, {}, unknown, {}, {}, import("vue").ComponentOptionsMixin, import("vue").ComponentOptionsMixin, {}, string, import("vue").VNodeProps & import("vue").AllowedComponentProps & import("vue").ComponentCustomProps, Readonly<import("vue").ExtractPropTypes<{
    foo: {
        type: import("vue").PropType<string>;
    };
}>>, {}, {}>;
export default _default;

I would expect the JSDoc comment to be included in the resulting *.vue.d.ts file, but that is not the case.

Runtime syntax works

When using the runtime syntax, the comment is emitted as expected:

<script setup lang="ts">
defineProps({
  /**
   * This is an example prop
   */
  foo: {
    type: String,
  },
});
</script>

<template>Hello {{ foo }}</template>

Resulting d.ts:

declare const _default: import("vue").DefineComponent<{
    /**
     * This is an example prop
     */
    foo: {
        type: StringConstructor;
        default: string;
    };
}, {}, unknown, {}, {}, import("vue").ComponentOptionsMixin, import("vue").ComponentOptionsMixin, {}, string, import("vue").VNodeProps & import("vue").AllowedComponentProps & import("vue").ComponentCustomProps, Readonly<import("vue").ExtractPropTypes<{
    /**
     * This is an example prop
     */
    foo: {
        type: StringConstructor;
        default: string;
    };
}>>, {
    foo: string;
}, {}>;
export default _default;

Final notes

When using the component within the same project, the hover documentation does correctly display in both cases, so it seems to only affect the emitted declaration files.